Pick



Nov. 26, 1935. H. c. sHAuGHENcY PICK Filed June' 5, 1935 Jag. 1.

2 www.

Patented Nov. 26, 1935 UNITED .STATES ATENT OFFICE l Prox Massachusetts'Application June 5, 1933, Serial No. 674,387

6 Claims.

This invention relates to picks, and more particularly, but notexclusively, to picks especially designed for use with pneumatic hammertools.

An object of this invention is to provide an improved picking tool.Another object is to provide an improved picking tool having a pickpoint of improved shape, whereby the material acted on by the tool isbroken down in an improved manner. A further object is to provide 4animproved picking tool particularly adapted to use for mining purposes,and more particularly for use in the mining of coal or similar cleavablematerials. rlhese and other objects will, however, hereinafter morefully appear.

In the accompanying drawing there is shown for purposes Yof illustrationone form which the invention may assume in practice.

Fig. 1 is a diagrammatic view showing the picking tool in operativeposition with respect to the work.

Fig.v2 is a side elevational view of the illustrative form of theimproved picking tool.

Fig. 3 is an enlarged side elevational View of the improved pick point.

Fig. 4 is a cross sectional view taken on line ll-fl of Fig. 3. l

Fig. 5 is a plan view of the pick point shown in Fig. 3.

In this illustrative form of the invention the improved picking tool,generally designated l, is preferably operated by a pneumatic hammertool such as a pick hammer or a pneumatic rock drill, although ifdesired the tool shank may be percussively actuated by other power meansor by manually operated hammer devices, Vit not being desired to limitthe use of the pick to employment with any particular hammer tool.

In the development of the improved pick disclosed herein, severaldifferent shapes of pick points have been experimented with; and after anumber of tests the form shown was found most eicient under mostconditions. The improved pick comprises a relatively long body or shank2 which, throughout a major portion of its length, is polygonal in crosssection, preferably hexagonal, but in certain types of picks the bodymay be round, or other shapes in cross section.

Formed on the rear end portion of the pick body,V

when actuation by a pneumatic hammer motor is to be effected, is a usualcollared shank 3 designed for reception in the chuck of the pickactuating tool. The improved pick point, in side elevation, as viewed inFig. 3, has, in a preferred form, an arcuate or convex` bottom surface 4extending from the pick body to the pick point and terminating at thelatter in the plane of the top surface of the pick body, as shown inFig. 2. The convex surface is desirably formed on a curve which causesthe maximum top to bottom 5 dimension of the working part to exceed thethickness of the shank or body 2. The pick point in plan, as viewed inFig. 5, is wedge shaped. The side surfaces 5 and l extending from thepick body or shank to the pick point converge both 10 upwardly andtowards the pick point. These side surfaces are plane surfaces and, asjust indicated, incline downwardly and outwardly with respect toeachother, in the manner sho-wn in cross section in Fige, andterminate inthe top surface 5 15 and the curved lower surface d. As shown in Fig. 4,the pick point is polygonal in cross section and the lower surface 4 issomewhat greater in width than the top surface 5, due to the divergenceof the plane side surfaces B and 'l of the point. 20 The surfaces 4, 5,E and 'l all come toa point at the cutting end of the pick, at the pickpoint.

It will be evident that it is not essential that the surfaces 5, A6 and'l be plane, and that surface 5 may be slightly concave, Vfor example,and surfaces 5 and 1 may be either slightly concave or slightly convex,though the construction illustrated is very satisfactory. f

It will thus be seen that as the picking tool is precussively actuated,the sharp point of the pick penetrates the coal, and due to its peculiarwedge shape cleaves or shears the coal, thereby tending to break loosethe coal. By the provision of the curved lower surface l5 the pickingtool tends to move upwardly in an arcuate path, 35 when operated in theposition shown in Fig. l, thereby facilitating the penetrating movementof the pick point and the breaking down of the coal. As showndiagrammatically in Fig. 1, the mine roof is shown at 8 and the layer ofcoal at 9. 40 As the pick penetrates the coal in the manner shown inFig. l, the coal tends to break along the curved line Eil, due to theupward arcuate move ment of the pick, thereby breaking the portion l!from the mine wall, this operation being re- 45 peated by successivepenetrating thrusts of the pick point Within the coal, and, as a result,the coal or other material attacked is broken down in large lumps. Dueto the greater width of the surface 4, it serves to skid the bitupwardly 50 very effectually. The convergence upwardly of the surfaces 5and l also facilitates a wedging or splitting action, so that vcleavageis very effectively accomplished. The proportions of the top surfacegive a sufficient upward wedging ac- 55 tion, without preventing thesplitting effect just mentioned. The forward taper also provides alateral splitting action, so that the tool as it penetrates has atransverse ripping effect, which supplements the vertical splittingaction of the surfaces 6, l on upward skidding due to the curvature ofsurface 4, and the upward bodily wedging action of surface 5. From thesefacts the suitability of this tool for its purpose and its advantageswill be clearly apparent to those skilled in the art.

While there is in this application specically described one form whichthe invention may assume in practice, it will be understood that thisform of the same is shown for purposes of illustration and that theinvention may be modified and embodied in various other forms withoutdeparting from its spirit or the scope of the appende'd claims.

What I claim as new and desire to secure by Letters Patent is: Y

1. A picking tool comprising a substantially straight body having ashank at one end, and. a pick point formed on the body at the workingend of the pick and formed rigid and integral with the main body, saidpick point being formed with a plane top surface, a convex lower surfaceand relatively inclined plane side surfaces extending for the length ofthe point and converging upwardly towards said plane top surface andalso forwardly into a pointed end at the working end of the pick, saidpoint being polygonal in cross section.

2. A picking tool comprising a substantially straight body having ashank at one end, and a pick point formed on the body at the working endof the pick and formed rigid and integral with the main body, said pickpoint being formed with a plane top surface, a convex lower surface andrelatively inclined side surfaces converging forwardly into a pointedend at the working end of the pick and said side surfaces slantingoutwardly and downwardly toward said convex surface, the latter being ofan area greater than the area of the sum of the areas` of the topsurface and the projections on a surface parallel to said top surface ofthe side surfaces.

3. A picking tool comprising a substantially straight body having ashank at one end, and a pick point formed on the body at the working endof the pick and formed rigid and integral with the main body, said pickpoint being formed with a plane top surface, a convex lower surface andrelatively inclined side surfaces converging forwardly into a pointedend at the working end of the pick and said side surfaces slantingoutwardly and downwardly toward said convex surface, said pick pointbeing formed trapezoidal in cross section.

4. A picking tool adapted for coal mining and comprising a shankcomposed of a substantially straight bar extending throughout the majorportion of the length of the tool and a relatively short working endterminating in a point and having a plane surface lying in a plane witha surface element of said bar, lateral plane surfaces diverginglongitudinally from the point rearwardly and transversely of the toolfrom said first mentioned surface, and a fourth surface extending fromsaid point rearwardly to said bar and having curved lines of junctionwith said lateral surfaces, said working end of maximum dimensionperpendicular to said first mentioned surface at a point between itsjunction with the bar and its point.

5. In a tool of the character which comprises an elongated rectilinearshank and a relatively short wo-rking end and which is percussivelyactuated rectilinearly in a direction axially of its shank, a shank, anda working end terminating in a point, said end having a convex surfaceextending from said point rearwardly and a narrower, plane, forwardlytapering surface opposite said convex surface and parallel to the axisof the shank and extending to said point, and lateral surfaces extendingto said point and diverging both rearwardly from said point and fromsaid plane surface towards said convex surface.

6. In a tool of the character which comprises an elongated rectilinearshank and a relatively short working end and which is percussivelyactuated rectilinearly in a direction axially of its shank, a shank, anda working end terminating in a point substantially in a common planewith an element of the surface of the shank, said end having a convexsurface extending from said point rearwardly and a narrower, plane,forwardly tapering surface opposite said convex surface and parallel tothe axis of the shank and extending to said point, and lateral planesurfaces extending to said point and diverging both rearwardly from saidpoint and from said plane surface towards said convex surface.

HARVEY C. SHAUGHENCY.

